fbdev: add support for handoff from firmware to hw framebuffers

With KMS we have ran into an issue where we really want the KMS fb driver
to be the one running the console, so panics etc can be shown by switching
out of X etc.

However with vesafb/efifb built-in, we end up with those on fb0 and the
KMS fb driver on fb1, driving the same piece of hw, so this adds an fb
info flag to denote a firmware fbdev, and adds a new aperture base/size
range which can be compared when the hw drivers are installed to see if
there is a conflict with a firmware driver, and if there is the firmware
driver is unregistered and the hw driver takes over.

It uses new aperture_base/size members instead of comparing on the fix
smem_start/length, as smem_start/length might for example only cover the
first 1MB of the PCI aperture, and we could allocate the kms fb from 8MB
into the aperture, thus they would never overlap.

[[email protected]: coding-style fixes]
Signed-off-by: Dave Airlie <[email protected]>
Acked-by: Peter Jones <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Krzysztof Helt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 0ecf6b76a401c043e00a12b3b027a07ef14cce01..8e28e5993df5b5607896db9c8c30a226faf1790d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -504,6 +504,14 @@ static int intelfb_create(struct drm_device *dev, uint32_t fb_width,
        info->fbops = &intelfb_ops;
 
        info->fix.line_length = fb->pitch;
+
+       /* setup aperture base/size for vesafb takeover */
+       info->aperture_base = dev->mode_config.fb_base;
+       if (IS_I9XX(dev))
+               info->aperture_size = pci_resource_len(dev->pdev, 2);
+       else
+               info->aperture_size = pci_resource_len(dev->pdev, 0);
+
        info->fix.smem_start = dev->mode_config.fb_base + obj_priv->gtt_offset;
        info->fix.smem_len = size;
 

diff --git a/drivers/video/efifb.c b/drivers/video/efifb.c
index 8dea2bc927054783658183f662d9644e2eb27efc..eb12182b20598861937b46496b8716efcae1e366 100644 (file)
--- a/drivers/video/efifb.c
+++ b/drivers/video/efifb.c
@@ -280,6 +280,9 @@ static int __init efifb_probe(struct platform_device *dev)
        info->pseudo_palette = info->par;
        info->par = NULL;
 
+       info->aperture_base = efifb_fix.smem_start;
+       info->aperture_size = size_total;
+
        info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
        if (!info->screen_base) {
                printk(KERN_ERR "efifb: abort, cannot ioremap video memory "
@@ -337,7 +340,7 @@ static int __init efifb_probe(struct platform_device *dev)
        info->fbops = &efifb_ops;
        info->var = efifb_defined;
        info->fix = efifb_fix;
-       info->flags = FBINFO_FLAG_DEFAULT;
+       info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
 
        if ((err = fb_alloc_cmap(&info->cmap, 256, 0)) < 0) {
                printk(KERN_ERR "efifb: cannot allocate colormap\n");

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index d412a1ddc12fabb50df8562af40b5df25351d2bd..f8a09bf8d0cdecb0963116a4fb7a7d3793ed798d 100644 (file)
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1462,6 +1462,16 @@ static int fb_check_foreignness(struct fb_info *fi)
        return 0;
 }
 
+static bool fb_do_apertures_overlap(struct fb_info *gen, struct fb_info *hw)
+{
+       /* is the generic aperture base the same as the HW one */
+       if (gen->aperture_base == hw->aperture_base)
+               return true;
+       /* is the generic aperture base inside the hw base->hw base+size */
+       if (gen->aperture_base > hw->aperture_base && gen->aperture_base <= hw->aperture_base + hw->aperture_size)
+               return true;
+       return false;
+}
 /**
  *     register_framebuffer - registers a frame buffer device
  *     @fb_info: frame buffer info structure
@@ -1485,6 +1495,23 @@ register_framebuffer(struct fb_info *fb_info)
        if (fb_check_foreignness(fb_info))
                return -ENOSYS;
 
+       /* check all firmware fbs and kick off if the base addr overlaps */
+       for (i = 0 ; i < FB_MAX; i++) {
+               if (!registered_fb[i])
+                       continue;
+
+               if (registered_fb[i]->flags & FBINFO_MISC_FIRMWARE) {
+                       if (fb_do_apertures_overlap(registered_fb[i], fb_info)) {
+                               printk(KERN_ERR "fb: conflicting fb hw usage "
+                                      "%s vs %s - removing generic driver\n",
+                                      fb_info->fix.id,
+                                      registered_fb[i]->fix.id);
+                               unregister_framebuffer(registered_fb[i]);
+                               break;
+                       }
+               }
+       }
+
        num_registered_fb++;
        for (i = 0 ; i < FB_MAX; i++)
                if (!registered_fb[i])
@@ -1586,6 +1613,10 @@ unregister_framebuffer(struct fb_info *fb_info)
        device_destroy(fb_class, MKDEV(FB_MAJOR, i));
        event.info = fb_info;
        fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
+
+       /* this may free fb info */
+       if (fb_info->fbops->fb_destroy)
+               fb_info->fbops->fb_destroy(fb_info);
 done:
        return ret;
 }

diff --git a/drivers/video/vesafb.c b/drivers/video/vesafb.c
index d6856f43d241df13d14ab43113c9472387ecbdef..bd37ee1f6a251bce027920a4eab805b0bbcfc3de 100644 (file)
--- a/drivers/video/vesafb.c
+++ b/drivers/video/vesafb.c
@@ -174,8 +174,17 @@ static int vesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
        return err;
 }
 
+static void vesafb_destroy(struct fb_info *info)
+{
+       if (info->screen_base)
+               iounmap(info->screen_base);
+       release_mem_region(info->aperture_base, info->aperture_size);
+       framebuffer_release(info);
+}
+
 static struct fb_ops vesafb_ops = {
        .owner          = THIS_MODULE,
+       .fb_destroy     = vesafb_destroy,
        .fb_setcolreg   = vesafb_setcolreg,
        .fb_pan_display = vesafb_pan_display,
        .fb_fillrect    = cfb_fillrect,
@@ -286,6 +295,10 @@ static int __init vesafb_probe(struct platform_device *dev)
        info->pseudo_palette = info->par;
        info->par = NULL;
 
+       /* set vesafb aperture size for generic probing */
+       info->aperture_base = screen_info.lfb_base;
+       info->aperture_size = size_total;
+
        info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
        if (!info->screen_base) {
                printk(KERN_ERR
@@ -437,7 +450,7 @@ static int __init vesafb_probe(struct platform_device *dev)
        info->fbops = &vesafb_ops;
        info->var = vesafb_defined;
        info->fix = vesafb_fix;
-       info->flags = FBINFO_FLAG_DEFAULT |
+       info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE |
                (ypan ? FBINFO_HWACCEL_YPAN : 0);
 
        if (!ypan)

diff --git a/include/linux/fb.h b/include/linux/fb.h
index 330c4b1bfcaa58b32907cd9f050c9cc67b097cb0..3c5562a52167bc69da24edd6b9684008c3356c76 100644 (file)
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -677,6 +677,9 @@ struct fb_ops {
        /* get capability given var */
        void (*fb_get_caps)(struct fb_info *info, struct fb_blit_caps *caps,
                            struct fb_var_screeninfo *var);
+
+       /* teardown any resources to do with this framebuffer */
+       void (*fb_destroy)(struct fb_info *info);
 };
 
 #ifdef CONFIG_FB_TILEBLITTING
@@ -786,6 +789,8 @@ struct fb_tile_ops {
 #define FBINFO_MISC_USEREVENT          0x10000 /* event request
                                                  from userspace */
 #define FBINFO_MISC_TILEBLITTING       0x20000 /* use tile blitting */
+#define FBINFO_MISC_FIRMWARE           0x40000 /* a replaceable firmware
+                                                 inited framebuffer */
 
 /* A driver may set this flag to indicate that it does want a set_par to be
  * called every time when fbcon_switch is executed. The advantage is that with
@@ -854,7 +859,12 @@ struct fb_info {
        u32 state;                      /* Hardware state i.e suspend */
        void *fbcon_par;                /* fbcon use-only private area */
        /* From here on everything is device dependent */
-       void *par;      
+       void *par;
+       /* we need the PCI or similiar aperture base/size not
+          smem_start/size as smem_start may just be an object
+          allocated inside the aperture so may not actually overlap */
+       resource_size_t aperture_base;
+       resource_size_t aperture_size;
 };
 
 #ifdef MODULE